1. Field of the Invention
The present invention relates to pyrimidine and pyridine derivatives or pharmacologically acceptable salts thereof, which have an excellent inhibitory effect on acyl-CoA:cholesterol O-acyltransferase (ACAT).
The compounds of the present invention have the effect of reducing serum cholesterol by inhibiting the absorption of cholesterol from intestinal tract and suppress the accumulation of cholesterol esters in the arterial wall. Therefore, they are useful as a prophylactic and therapeutic agent for hypercholesterolemia, atherosclerosis and various diseases caused by them (for example, ischemic heart diseases such as myocardial infarction, and cerebrovascular diseases such as cerebral infarction and cerebral apoplexy).
2. Related Art
Japanese Patent Unexamined Publication Nos. 61-40272 and 1-207234 disclose compounds (e.g. 5-[3-(2-dimethylaminoethyl)ureido]-6-methyl-4-(3-nitrophenyl)-2-phenylpyri midine) and 3-[3-(2-dimethylaminoethyl)ureido]-4-(3-nitrophenyl)-2-methyl-6-phenylpyri dine, respectively, as pharmaceutical compositions for curing cerebrovascular diseases. Japanese Patent Unexamined Publication No. 5-320028 discloses compounds such as 4-(phenylureido)pyridine and 4-(phenylureido)pyrimidine as hair tonics. But, these references do not describe the above compounds as having ACAT-inhibitory activity or serum-cholesterol-lowering activity, at all. Japanese Patent Unexamined Publication Nos. 62-258366, 63-253060, 2-258756 and 5-92950 disclose pyrimidine and pyridine derivatives having ACAT-inhibitory effect, but the effect of all the pyrimidine and pyridine derivatives are not sufficient.